The present invention relates to an automotive headlamp testing method and apparatus for testing the headlamp beam axis, particularly the low beam axis of the headlamps of an automobile on an automobile assembly line.
Generally, in an inspection section annexed to an automobile assembling line, a headlamp test is conducted to check whether the headlamp beam is oriented correctly. As shown in FIG. 1, this headlamp test is conducted by applying the low beam of the headlamp to a screen 11 which is positioned ahead of the automobile on the assembling line and has a reference or standard mark 15 and checking whether the boundary line 12 referred to as "cut off line" hereunder between the dark area 13 and the bright area 14 of the low beam is aligned with the standard mark 15 on the screen 11. If the cut off line 12 fails to be so aligned, the headlamp beam axis is adjusted to bring the cut off line 12 into alignment with the standard mark 15.
This conventional headlamp testing method, however, encounters the following problems.
Namely, it is not easy to visually check the alignment of the headlamp beam axis because the cut off line 12 does not actually appear so distinctively as shown in FIG. 1. Checking is difficult and the checking accuracy is low particularly in the case where one assembling line is used for the assembly of a plurality of types of automobiles, because in such a case a plurality of standard marks 15, corresponding to different types of automobiles, are concentrated in a limited area on the screen 11.
For the same reasons, the adjustment of the headlamp beam axis is difficult and cannot be conducted with sufficient accuracy.